Injection-molding machines that inject resin material into a metal mold to manufacture a resin article are widely used in practice. In injection-molding machines, mass production molding is started after the molding conditions have been manually entered by a worker. However, the molding conditions differ according to the shape of the molded article and the properties of the resin. For this reason, the molding conditions must be determined before mass production molding can take place, and work must be performed to determine the molding conditions.
The work of determining the molding conditions is preferably carried out by a skilled worker having considerable knowledge and experience. However, if no such skilled worker is available, an unskilled worker must be assigned to do the work of determining the molding conditions.
In this case, it is useful to use a support system referred to as an expert system, as disclosed in, e.g., JP 2001-88187 A. In other words, the molding conditions can be derived even by an unskilled worker when an expert system is used. The system disclosed in JP 2001-88187 A will be described with reference to FIG. 12 hereof.
In the system shown in FIG. 12, information data 102 related to the molded article and the metal mold is entered by the worker to an initial molding condition determination unit 103 with the aid of an input unit 101. Machine data 105 related to the injection-molding machine is entered from a machine database file 104, and resin data 107 related to the resin material is entered from a resin database file 106 into the initial molding condition determination unit 103. The initial molding condition determination unit 103 calculates the molding conditions 108.
A flow analyzer 109 predicts the parameters that are present during and after molding on the basis of the molding conditions 108. When this prediction leads to molding defects, a molding condition correction unit 110 corrects the molding conditions. The worker enters the corrected molding conditions 108 to the flow analyzer 109, and the various parameters that are present during and after molding are predicted again. The worker repeats a series of procedures until the molded article becomes an acceptable product. The final molding conditions are the suitable molding conditions 108.
The worker is not required to actually perform injection molding because the flow analyzer 109 predicts the various parameters that are present during and after molding. This process is advantageous in that more suitable molding conditions can be obtained and wasted time and costs can be eliminated by repeating molding conditions correction and flow analysis without performing test injection molding.
In other words, the worker can know the suitable molding conditions 108 by merely entering molding and metal mold information 102 using the input unit 101.
The suitable molding conditions 108 obtained in this manner still generate molding defects when actual injection molding is carried out using an injection-molding machine. The worker is unable to determine which of a plurality of molding conditions to correct when molding defects are generated. This is because the process for computing the suitable molding conditions 108 is a black box for the worker.
In other words, the system described in FIG. 12 is not advantageous from the standpoint of training and developing an unskilled worker.
In view of the above, a technique for allowing the worker to be aware of the relationship between the molding conditions and the molded article using a viewable graph has been proposed in, e.g., JP 2006-123172 A. The technique proposed in JP 2006-123172 A will be described with reference to FIG. 13 hereof.
A birefringence graph 121, which is a single evaluation item of the molded article (disc substrate), can be displayed on a display unit 120 provided to the injection-molding machine for injecting the disc substrate, as shown in FIG. 13.
The birefringence graph 121 provides a representation of the distance from the center of the molded article to the external periphery shown on the horizontal axis 122 and the birefringence shown on the vertical axis 123, resulting in a curved line 124.
Also provided below the birefringence graph 121 are displays 125 of the molding conditions composed of “Compression Start Position,” “Heating Cylinder Temperature,” “Injection Velocity,” and “Mold Clamping Force,” as well as increase buttons 126 and decrease buttons 127 associated with the displays 125.
The worker moves the curved line 124 upward or downward by pressing the increase button 126 or the decrease button 127 associated with the “Compression Start Position,” for example. The curved line 124 is alternatively rotated.
Specifically, the worker can be visually made aware of the manner in which the birefringence graph 121 changes when the increase button 126 is pressed, and the worker can be visually made aware of how the birefringence graph 121 changes when the decrease button 127 is pressed. Since the birefringence graph 121 can be visually confirmed, the worker can more readily understand the process. For this reason, it is apparent that the technique shown in FIG. 13 is advantageous for worker training.
It should be noted that the plurality of molding conditions affects each other. For this reason, even if the relationship between a single molding condition and a single evaluation item is understood, such knowledge cannot necessarily be adequately applied to the operation of an actual injection-molding machine. Such knowledge is useful for training purposes, but is not useful for operating an injection-molding machine.
In view of this situation, there is a need for a support apparatus that is advantageous for training an unskilled worker and useful for operating an actual injection-molding machine.